1. Black Sea/Mediterranean EnvironmentVol. 14: 167-182

Diversity of Marine Ostraeoda (Crustaeea) on theNorthern Co as ts of Sea of Marmara (Turkey)

Marmara Denizi'nin Kuzey Kıyılarındaki DenizOstrakodlanmn Dağılımı

Cüneyt Kubanç *, Simten Nerdin Kubanç* and Hüseyin Akıncı*

*Istanbul University, Faculty of Science, Department of Biology, 34459,Vezneciler- Istanbul, TURKEY

Abstract

In this study the materials collected from the Northern coasts of Sea of Marmarabetween 1999- 2000 were evaluated and 33 species from 16 genera has beendetermined. Among these species Callistocythere diffusa, Loxoconcha littoralis andLoxoconcha pontica are new records for the Sea of Marmara. According to theSpermann analysis the primary hydrographical variables did not seem to be veryeffective in the distribution dynamics of the ostracod species in the Sea of Marmara.However according to the MDS ana1ysis, it has been observed that Cyprideis torosawas affected by temperature, Xesteloberis communis by sa1inity, Loxoconcharhomboidea and Paracytheridea parallia by dissolved oxygen when compared toother species.

Keywords: Ostracoda, Sea of Marmara, Mediterranean Sea, Aegean Sea,,diversity

Introduction

The Sea of Marmara is a smaIl (size - 70 x 250 km) intercontinental basinconnecting the Black Sea and the Mediterranean Sea. The northern shelf areais narrow (5-10 km in width) compared to the southem shelf (-30 km inwidth), extends to 90-100 m water depth, widening eastwards and almostdisappears in the west, between Mürefte and Dardanelles. It extends parallelto the shoreline, widening to about ı2 km at the confluence of Bosphorusand in the vicinity of the Prince lslands, and tenninating in lzmit Gulf in theeast (Figure 1).

, *Corresponding author: kubac@istanbul.edu.tr

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Figure ı.Sea of Marmara and the sampling stations.

ııı" 29"

The oceanographic properties of the Sea of Marmara are influenced by theBlack Sea and the Aegean Sea through the Bosphorus Strait and theDardanelies, having permanent, two-Iayered, water stratification. Salinityvalue of the Black Sea at the entrance of the Bosphorus is 17.6 %0. The samevalue increases at 22 %0 towards south. The salinity of the upper layerincreases at 26 %0, affected by strong winds towards Dardanelies. Salinityvalue of the deep-water layer originated from Mediterranean is as high as38.5 %0 (Yüce and Türker 1991). Dissolved oxygen measurements fromsurface layer of Marmara are similar to the values of Black Sea water fromthe Bosphorus. It has been observed that the highest value is 11.7 mg/I inApril and lower than 7 mg/I in October (Salihoğlu and Mutlu 1999). Adissolved oxygen value of the surface water is near to the satiationdegreebetween 7.5-12.8 mg/I and changing related to temperature (Tuğrul andSalihoğlu 2000). Water temperature values are between 7-22 oc. The BlackSea current with a high dissolved oxygen and low salinity influences surfacewater of Northern Marmara obviously. During winter, the inflow of Aegeandeep water from Dardanelles reaches maximum and as it is denser than thesurface water, it sinks on the Western Marmara, which can be distinguishedwith low temperature, and high salinity (Yüce 1995). AIso NorthernMarmara Sea is oligotrophic in nature (Balkıs 2003).

The Sea of Marmara is now the recipient of a large amount of wastewaterdischarging from land-based sources. Pollution loading from Istanbul alone,the biggest city of Turkey in terms of population and industry, make up the

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major portion (40-65%) of the total anthropogenic discharges (Tuğrul andPolat 1995).

Stratification observed İn Marmara Sea with a separating haloeline layeraffects its faunal diversity İn many ways. üstracoda fauna of the MarmaraSea is affected especially by species from Mediterranean and Aegean Seas(Tunoğlu 1999, Nazik 2001, Kubanç 2002).

The aim of this study is to determinate the üstracoda fauna of the Northemcoasts of the Sea of Marmara which is under the threat of pollution and toreport, if any, species that would be new to Turkish waters.

Material and MethodsThe Northem coasts of Marmara Sea were sampled from 23 stations between1999, 2000 (Figure 1). Samples were obtained with a hand net made ofMuller fabric from the mediolittoral zone sweeping the bottom twice in anarea of 3 m2 approximately. Primary ecological variables (temperature,salinity and dissolved oxygen) were measured in the field using a WTWMultiline P4 measurement apparatus (Table 1).

Samples were fixed in 4% formaldehyde and later washed under pressurizedwater to separate the material from mud and detritus. üstracods wereseparated from 10 g of material per station under a stereomicroscope.Generic and specific features of carapace and sofi parts were examined inorder to identify different species.

Spermann rank order correlation was used to correlate the species number ofostracods and hydrographical variables (Siegel 1956). The Sorensensimilarity matrix (Sorensen 1948) was ca1culated in order to determine thesimilarity between the surrounding seas and the Northem coasts of the Seaof Marmara according to the ostracod species involved. Nonmetric Multi-Dimensional Scaling (MDS) analysis was performed to estimaterelationships between the ostracod community and hydrographic data(Clarke and Warwick 2001). Clustering was ca1culated with the Bray-CurtisSimilarity Index, based on Fourthroot transformation, in order to determinethe similarity between sampling stations. For the mathematical analysis ofthe samples the Shannon-Weaver Diversity Index (Zar 1984) and theEvenness Index (Pielou 1969) were calculated.

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•....•-.Jo

Table L'Some hydrographical variables, sediment type, coordinate and dates obtained for the stations.

Stations Date,

Coordinates Sediment typeTemperature Salinity Dissolved Species

(oC) (%0) oxygen (mg/I) numberi 30.10.1999 40° 53' 00" N - 29° 05' lO" E Gravel, sand, sea weed 17 22.2 9.1 72 30.10.1999 40° 52' lO" N - 29° 04' SS" E Sand, sea weed 17 22.4 9.2 103 30.10.1999 40° 52' lO" N - 29° 05' IO".E Sand, sea weed 17 22.4 9.9 84 31.10.1999 40° 52' 30" N - 29° 07' 30" E Gravel, sand, sea weed 18 22.5 9.7 55 31.10.1999 40° 50' 20" N - 29° 07' IS" E Sand, sea weed 17 22.3 6.7 86 31.10.1999 40° 51' SO" N - 29° 06' SO" E Sand, sea weed 17 22.5 7.3 II7 01.l1.l999 40° 53' lO" N - 29° 03' IS" E Gravel, sand, sea weed 13 22.6 8.2 48 02. 11.1999 40° 45' 30" N - 29° 22' 30" E Gravel, sand, sea weed 13 22.2 8.4 69 02.11.1999 40° 49' SO" N - 29° 16' 30" E Smail gravel, sand 14 22.3 7.7 13Lo 02.11.1999 40° 48' 40" N - 29° IS' 30" E Gravel, sand, sea weed 14 22.5 7.9 9II 03.11.1999 41° OL' OS" N - 28° 59' OS" E . Big stone, sea weed 12 22.6 5.9 912 03.11.1999 41 ° 00' 25" N - 28° 32' 45" E Sand, sea weed 14 19.7 7.6 413 04.1 1.1999 41° 03' SS" N - 28° 17' 00" E Gravel, sand, sea weed 14 22.4 7.9 914 04.1 1.1999 40° 58' lO" N - 27° 55' lO" E Gravel, sand, sea weed 14 23.3 8.2 5IS 20.02.2000 40° 36' 00" N - 27° 04' 00" E Gravel, sand, sea weed 7 22.5 10.2 716 20.02.2000 40° 39' 20" N - 27° 13' 35" E. Gravel, sand, sea weed 7 22.8 9.2 917 20.02.2000 40° 43' 20" N - 21" 19' 20" E Gravel, sand, sea weed 7 22.8 9.8 1218 21.02.2000 40° 54' 00" N - 27° 28' 00" E Gravel, sand, sea weed 8 22.6 10.4 819 21.02.2000 40° 58' 30" N - 27° 31' 40" E Gravel, sand, sea weed 8 22.2 8.6 920 22.02.2000 40° 59' 00" N - 27° 51' IS" E Gravel, sand 7 21.8 10.2 721 22.02.2000 41 ° 02' 20" N.- 28° 02' 30" E Gravel, sand, sea weed 8 22.6 9.2 1422 22.02.2000 41° OL' 50" N -28° 27' OO"E Gravel, sand, sea weed 8 22.6 9.4 623 20.05.2000 40° 58' 40" N - 28° 46' 00" E Gravel, sand, sea weed 15 20.0 11.2 8

Results

Identified ostracoda species from 23 stations are listed in table 2. Three ofthem .(Callistocythere diffusa Muller, Loxoconcha pontica Klie andLoxoconcha littoralis Muller) were recorded in the- Sea of Marmara for thefirst time. Most of the ostracods belong to genera Loxoconcha. Thegeneralist species that were found throughout the who le of this research wereCosta edwardsi (f= 69.5%), Xestoleberis communis (f= 69.5%), Loxoconcharhomboidea (f=56.5%), Callistocytherediffusa (f= 48%), Urocythereisbritannica (f= 48%) and Loxoconcha minima (f= 48%). LoxocorichaZittoralis, Loxoconcha pontica, Xestoleberis aurantia and Xestoleberiscornelli were observed to be the rare species (f= 4%). The highest speciesnumbers were recorded at stations 21 (14 species) and 9 (13 species)followed by stations 17 (12 species) and 6 (11 species). The lowest numbersof species were recorded for station s 7 and 12 (4 species each).

Cluster analysis (Figure 2) made to combine the stations according to thespecies they involve, showed two distinct groups. The' highest similarityamong the stations appeared to be between stations 2 and 10 (%78.55) with8 associated species noticed at both. The lowest similarity among thestation s was found between stations II and 15 (8.33%) with only 1associated species. The maximum abundance of ostracods was observed atstation 6 (151 individuals) the lowest abundance was at station 12 (13individuals) (Table 2).

Figure 2.Similarity of 23 stations located in the Northem Sea of Marmaraaccording to the OCCUITenceof different species.

~----------------",------------13.----- "r---------- ••L-.--------16

J--c=~==='. lı,.L----c==::c::========="LI",."

_----··-s,.._--'-----------~-------lt ~';.Shulladlr Hi 100

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Table 2.The abundance and frequency (f) of each identified species in the Northem Sea of Marmara.

---ıN

Station numbersSpecies

i 2 3 4 S 6 7 8 9 Lo II 12 13 14 IS 16 17 18 19 20 21 22 23 f(%)

Callistocvthere diffıısa Muller S 9 3 6 1 II 7 2 2 3 i 48Callistocythere lobiancoi (Muller) lA IS II 16 7 2 S 30Cvprideis torosa (Jones) 16 18 14 35 22 8 3 30Acantocytlıereis hvsırix (Reuss) 2 S 13 13Cvthereis dunelmensis (Norman) i 3 9Carinocvthereis aff. antiauaıa Muller 2 i S 13Carinocythereis antiquata (Baird) 4 i 9Carinocvıhereis quadridenıata (Baird) 6 7 2 9 17Costa edwardsi (Roemer) 49 IS 21 18 22 S 12 24 16 12 Lo 1 19 2 1 i 69.5Costa batei (Brady) 2 1 S 3 6 9 1 8 6 39Hiltermannicythere ıurbida (Muller) 3 i 1 13Aurila speveri (Brady) 12 6 18 2 2 i 7 16 8 LO 43Aurila convexa (Baird) LI 35 19 1 S 17 1 2 35Aıırila prasina Barbeito-Gonzales 1 2 9Urocvthereis britannica Athersuch 25 lA 9 2 1 S 2 14 9 18 25 48Loxoconcha minima Muller 3 8 S 1 i 9 5 8 3 2 7 .48Loxoconcha rlıomboidea (Fischer) S 14 6 2 i 6 LI 7 9 13 4 IL 34 56.5Loxoconclıa pontica Klie i 4Loxoconc/ıa stellifera Muller 4 7 i 1 2 22Loxoconcha littoralis Muller . i 4Loxoconcha tıımida Chapman . S 3 9Paracytlıeridea parallia Barbeito-Gonza1es 41 IS 4 . 9 7 6 26

Station numbers

Species i 2 3 4 5 6 7 8 9 ıo ii 12 13 14 15 16 17 18 19 20 21 22 23 f(%)Pseudocytherura calcarata (Seguenza) 4 1 5 3 12Semicytherura rarecostata

LO 8 2 4 5 6 8 30Bonaduce,Ciampo,MasoliSemicvtherura incongruens (Muller) i 6 1 3 i i 26Semicytherura inversa (Seguenza) 13 3 7 13Cytheropteron punctatum Hanai 1 i 5 2 17Cytheropteron alatum Sars i 3 1 i 17Xestoleberis communis Muller 26 37 31 5 i 45 15 II ıo 6 8 14 i 3 9 21 69.5Xestoleberis aurantia (Baird) 3 4Xestoleberis comelli Caraion 5 4Xestoleberis decipiens Muller 5 i 2 13Paradoxostoma ensiforme (Brady) 7 i 9

•.....-...Ju..ı

Cluster analysis (Figure 3), made to combine the seas according to speciesthey involve, showed that the Mediterranean and the Aegean Sea had thehighest similarity (86%) the similarity of the Sea of Marmara to these twoseas is 77%. The similarity of the Black Sea to the others is only 51%.

Figure 3. Dendrogram constructed from Sorensen similarity matrix betweenthe seas according to the species involved.

Black Sea

Sea of Marmara

Mcditcrranean Sea ---- .•.•

Aegean Sea

100 90 70 6080Similarity % 50

During the course of this study, values of temperature, salinity and dissolvedoxygen were 12-18 "C, 19.7-23.3 %0 and 5.9-11.2 mgl', respectively. (Table1) The values of temperatures recorded in the studied area are consistentwith the seasonal changes (Balkıs 2003). The lowest salinity value wasrecorded for station 12 (19.7 %0) and all, other stations were recorded around22%0 because of being affected by the Black Sea current.

The result of the diversity index of Shannon- Weaver showed that the highestdiversity index (H') was obtained at station 9 (H'=3.28) and 21 (H'=3.29),and the lowest at station 12 (H'=1.35). The result of Evenness Index showedthat the highest Evenness Index (J') was obtained at station 7 (1'= 0.97), andthe lowest at station 12 (J'= 0.67) (Figure 4).

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Figure 4.Annual varıatıons of the Shannon-Weaver Index (H') andEvenness Index (J') according to stations.

The Spermann analysis was performed in order to determine the relationshipbetween the species of Ostracoda species and the primary hydrographicalvariables, however no significant relationship was observed. MDS analysisrevealed that, Cyprideis torosa was affected by temperature, Xesteloberiscommunis by salinity, Loxoconcha rhomboidea and Paracytheridea paralliaby dissolved oxygen when compared to other species (Figure 5).

Figure 5.Multi-Dimensional Scaling (MDS) plot in two dimensions for theostracod community in the Northem Coasts of Marmara Sea with relation totemperature, salinity and oxygen.

3 5 7 9 11 13 15 17 19 21 23Stations numbers

1

i -6- H' --- 1'1

C.io~sa •Tt~puaturt C.edwardsii•

A.conveı:a• •Other specıes.itU. biUannica•

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Discussion

Ostracods are of great importance in benthic populations of Turkish marineecosystems. in the Turkish Seas, 225 ostracod species up to now wereidentified. A total of 65 ostracod species has been identified from the BlackSea (Kılıç 1992-200 i, Tunoğl u 2002 and Kubanç 2003) . Nazik (2001),Nazik et aL. (1999), Kubanç and Kılınçarslan (2001), Kubanç (2002) andGülen et aL. (1990) observed 46, 44, 16, 25 and 22 ostracod species fromMarmara Sea, respectively. Finally up to now, a total of 79 ostracod specieswere identified in the Marmara Sea. So far, a total of 132 ostracod specieshas been defined from the Aegean Sea (Kubanç and Altmsaçlı 1990, Kubanç1995-1999, Şafak 1999, Meriç et aL.2002).

These cosmopolitan species, Costa edwardsi, Xestoleberis communis,Loxoconcha rhomboidea, Urocythereis britannica, which were all recordedin this study were recorded before from the Sea of Marmara (Gülen eta1.1990; Nazik et aL. 1999, Nazik 2001, Kubanç and Kılınçarslan 2001,Kubanç 2002), the Aegean Sea (Kubanç 1995, Şafak 1999, Kubanç 1999,Meriç et aL. 2002), and the Black Sea (Kılıç 1992, 2001, Tunoğlu 2002 andKubanç 2003). It is possible that the se species are euryhaline species as theywere recorded from different areas with wide ranges of salinity. Also one ofthe generalist species in this study, Callistocythere diffusa was recordedbefore from the Black Sea (Kılıç 2001) and Northem Aegean Sea(Stambolidis 1985) and this species was recorded for the first time with thisstudy from the Sea of Marmara. Most rarely observed species, Xestoleberisaurantia and Xestoleberis cornelli were recorded before from the Black Sea(Kılıç 2001), the Sea of Marmara (Nazik et aL. 1999, Nazik 2001) andNorthem Aegean Sea (Şafak 1999, Meriç et aL.2002). Loxoconcha littoraliswas recorded before from the Black Sea (Kubanç 2003) and NorthemAegean Sea (Stambolidis 1985), alsa Loxoconcha pontica was reported to bepresent from the Black Sea before (Kılıç 2001, Schomikov 1969). Both ofthese Loxoconcha species are new records for the Sea of Marmara. Theseostracod compositions in the Sea of Marmara reflect the more diverseAegean Sea and the less diverse Black Sea ostracod fauna (Figure 3).

Dissolved oxygen content of the lower layer reduces from the Dardanelles toBosphorus due to limited vertical mixing of the two water masses. Thecirculation pattem of both the upper and lower layers changes seasonally.The upper layer, entering from the strait of Istanbul, initially flows to theSouth, but then inclines to the west, forming an "S" shaped jet flow, whereasduring fall and winter the jet becomes weaker due to low discharges from theBlack Sea, and has a tendeney flow over the northem shelf from the exit of

176

the Istanbul Strait (Beşiktepe et aL. 1994) Clusıer analysis (Figure 2) made tocombine the stations according to the species they involve, showed twodistinct groups. The first group is the stations starting from the exit of theBosphorus including the Prince Islands and the entrance of the Bay of ızmitand the second group is the stations from the Bosphorus to the Dardanelles.We think that the reason of this is the current regime of the Sea of Marmara.Only stations 12 and 19 are not congruent with this clustering. We think thatthe reason of this is the locations of these stations which are near ports,station 19 directly located inside the port. Consequently the ships arriving todocks are creating a difference in pollution.

The surface water of Northem Sea of Marmara, is in affected by atmosphericconditions, consequently dissolved oxygen values are higher during the coldseasons than warm seasons (Balkıs 2003). Our findings are congruent withthis. The lowest recorded dissolved oxygen value is in station II as it islocated on the entrance of the Golden Hom, which is the most denselypolluted region. An extensive study about the Golden Hom reveals that, thisregion is heavily polluted especially by domestic waste (Yüce 1972).

The Diversity index of Shannon-Weaver value is the highest for the station s9 and 21, which have the highest number of species. The lowest number ofspecies is observed for station 12 with the lowest value of Shannon-WeaverDiversity index. AIso the lowest Evenness value is observed in station 12.However the highest Evenness value is for station 7 the reason for thisprobably is evenly distributed individual number of species that are not aslow as general individual numbers. This situation is probably showing thesigns of ecological degeneration. One can assume that the origin of thisdegeneration is from different sources as the species compositions of thesestations are different.

The findings of (Algan et aL. 2004) related to the pollution of the NorthemSea of Marmara were given with the table below (Table 3). According to thetable the values of Cr and Pb are higher than the Shale average values(Krauskopf 1979). According to AIgan et aL. (2004) the northem shelfsediments contain slightly lower metal values compared to tho e of thesouthem shelf. Mean values of metals in both of the shelf sediments aregenerally lower than those for the average crust (Krauskopf 1979), exceptfor Pb and Cr (Table 3). The reason of these high values of the se elements isthe land based anthropogenic (industrial) discharges. Especially the exit ofthe Bosphorus to the Sea of Marmara is under this influence. However theregion does not show the same degree of pollution like similar regions,because of the strong currents specific for the region. AIso when compared

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Heavy Metals Mean Range Shale AverageAI (0/0) 5.7 2.4-8.8 9.2Fe (0/0) 2.9 0.6-5.2 4.7

Mn (ppm) 300 100-616 850Cr (ppm) 130 31-654 100Ni (ppm) 56 11-116 80Co (ppm) 11 3-21 20Cu (ppm) 28 7-80 50Pb (ppm) 29 11-68 20Zn (ppm) 84 38-162 90Hg+ (ppm) 0.2 0.04-0.7 0.3

According to Algan et aL.(2004)

to the sediments from adjacent seasof the Sea of Marmara, the ranges ofMn, Co, Fe, Cu and Zn in the northern shelf are comparable to the sediment sfrom the southem shelf of the Black Sea (Algan et aL. 2004). Besides, theimpact of Istanbul's urban and industrial effluent is alsa apparent in the totalorganic carbon according to Albayrak et aL. (2006) Total organic carboncontent of sediments varied from 2. ı mglg to 22 mglg in the four area(Büyükçekmece, Silivri, Tekirdağ and Hoşköy) of the Northem Sea ofMarmara. Highest average total organic carbon content value was detected atBüyükçekmece transect (near Istanbul). Average values of total organiccarbon were decreased as the distance from Istanbul inereased. It was11.7mglg at Silivri transect, 8mglg at Tekirdağ transect and 5.3 mg/g atHoşköy transect (Albayrak et aL. 2006). While all of these results are notmeasured in our study theyare able to show the general pollution level of theSea of Marmara. The high values of Pb and Cr measured in the study ofAlgan et aL. (2004) from the vicinity of the Bosphorus exit to the Sea ofMarmara corresponds to the station 11 in our study. However these valuesare probably not very effective on the number of species due to the currentsin this region. Alsa the high values of organic Carbon measured in the studyof Albayrak et aL. (2006) corresponds to station 12 in this study. As it isstated before station 12 has the lowest number of species and the lowestvalue oh H'. Although not certainly the reason of this might be the pollution.Alsa the vicinity of Silivri in the study of Albayrak et aL.(2006) correspondsto our station 22 with a low value of H' (H'=1.99). Although this stationyielded only 6 species the individual number of Xestoleberis communis ishigher than other species.

Table 3. Heavy metal values between the years 1996-2000 for the NorthernSea of Marmara.

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This study has shown that the ostracod spccies present in the region and theirdistribution in the Northem Sea of Marmara. In this distribution it has beendeterrnined that some ostracod species are affected more by temperature,salinity and dissolved oxygen than other species. According to the clusteranalysis, studied station s were separated in two main groups: station sbetween l-f O and stations between 11-23 (excluding 19 and 23). The mostimportant difference between stations 11 and 23 and the others is apparentwhen the distributions of Xestoleberis and Loxoconcha taken in account(Table 2). The species of both genera are starting to occur (excluding X.communis and L. rhomboidea) in the se stations where the pollution levelsare higher than normaL. The studies about the heavy metal and Carbon levelsin this region (Algan et aL.2004), (Albayrak et aL. 2006) and another studyabout the positive relation with the populations of the species of Loxoconchawith the increase in pollution levels (AIvarez Zarikian et aL. 2000) aresupporting this situation. Excluding the cosmopolitan species of L.rhomboidea and X. communis in our study the distribution of all otherspecies of Loxoconcha and Xestoleberis between the stations 11 and 23makes us think that this region is more polluted than the regioncorresponding to the area between the stations 1 and 10. if the se findingscould be supported with future studies that include analysis about pollutiondetection the detailed determination of indicator ostracoda species forpollution may be possible.

Özet

Çalışma materyali 1999 sonbaharı ile 2000 yazı arasında Marmara Denizi'nin kuzeykıyılarında bulunan 23 istasyondan sağlanmıştır. Temel hidrografik veriler herörnekleme bölgesinden ayrı ayrı alınmıştır. Çalışmanın sonucunda MarmaraDenizi'nin kuzey kıyılarında üçü Türkiye için yeni kayıt 33 tür tayin edilmiştir.Ayrıca, bu ostrakot türlerinin geniş bir tuzluluk aralığında bulunduğu görülmüştür.

Hidrografik değişkenlerin bu bölgedeki ostrakot türleri üzerine herhangi önemli biretkisi olmadığı görülse de, özellikle Cyprideis torosa sıcaklıktan, Xesteloberiscommunis tuzluluktan ve Loxoconcha rhomboidea ve Paracytheridea paraLLiatürleride ise çözünmüş oksijenden diğer türlere göre daha çok etkilenmişlerdir. Buçalışmanın sonucunda söylenebilirki Loxoconcha, Paracytheridea, Xestoleberisgenusları diğer genuslara göre daha iyi bir kirlilik indikatörüdürler.

Acknowledgements

Authors are thankful to Dr. Neslihan Balkıs and Dr. Serhat Albayrak for the ir helpwith statistical appIications. Also thanks to Dr. Dinçer Gülen for his help inpreparation of the manuscript.

This study was supported by Istanbul University Research Fund with project numberı305/050599.

179

References

Albayrak S., Balkıs, H., Zenetos, A, Kurun A and Kubarıç, C. (2006). Ecologicalquality status of coastal benthic ecosystems in the Sea of Marmara. Marine PollutionBulletin, artiele in press.

Algan, O., Balkıs, N., çağatay, M. N. and Sarı, E. (2004). The sources of metalcontents in the shelf sediments from the Marmara Sea, Turkey. EnvironmentalGeology. 46: 932-950.

Alvarez Zarikian C. A, Blackwelder, P. L., Hood, T. ANelsen, T. Featherstone, C.(2000). Ostracods as indicators of natural and anthropogenically-induced changes incoastal marine environments. Coasts at the Millenium, Proceedings of the i7Uı

International Conference of The Coastal Society, Portland, OR USA, July 9-12,pp.896-905.

Balkıs N. (2003). Seasonal variations in the phytoplankton and nutrient dynamics inthe neritic water of Büyükçekmece Bay, Sea of Marmara. Journal of PlanktonResearch.25:703-717.

Beşiktepe Ş. T., Sur, H. ı. Özsoy, E. Latif, M.A Oğuz, T.and Ünlüata, Ü. (1994).The circulation and hydrography of the Marmara Sea. Prog Oceanogr. 34: 285-334.

Clarke, K.R. and Warwick, R. M. (2001). Change in marine communities: anapproach to statistical analysis and interpretation, second ed., PRIMER-E:Plymouth.

Gülen, D., Kubanç, C. and Altınsaçlı, S. (1990). Ostracoda. In: E. Meriç (ed.), LateQuaternary (Holocene) Bottom sediment of the southem Bosphorus and GoldenHorrı, İstanbul Teknik Üniv. Vakfı pp.43-53 ..

Kılıç, M. (1992). İstanbul Boğazı ve Karadeniz girişi Ostrakod (Crustacea) faunasıve zoocoğrafyası. MSc. thesis Istanbul University.

Kılıç, M. (2001). Recent ostracoda (Crustacea) fauna of the Black Sea coasts ofTurkey. Turk. J. Zool. 25:375-388.

Krauskopf K. B. (1979). Introduction to geochemistry, 20d edn. McGraw-HillKogakusha, Ltd. Tokyo, pp.617.

Kubanç, C. (1995). Ege Denizi Ostrakod (Crustacea) faunası. Ph. D. thesis, IstanbulUniversity. .

Kubanç C. (2002). Preliminary study on the ostracoda (Crustacea) fauna of MarmaraSea. Istanbul University Journal of Fisheries and Aquatic Sciences, 13: 65-80.

Kubanç C. (2003). Ostracoda (Crustacea) fauna of the Black Sea coasts of Istanbul.Turkish J. Marine Sciences, 9(2):147-162. .

Kubanç, c., Altınsaçlı, S.(1990). Ayvalık- Bergama lagün ostrakod faunası. X.Ulusal Biyoloji Kongresi Tebliğleri, Erzurum, pp.37-46.

180

Kubanç, N. (1999). Saroz Körfezi Ostrakod (Crustacea) faunası. Ph. D. thesis,Istanbul University.

Kubanç N., Kılmçarslan, Y. (2001). Aresearch on the Ostracoda (Crustacea) Faunaof Dardanelles, Istanbul University Journal of Fisheries and Aquatic Sciences, 12:49-60.

Meriç, E., Avşar, N. and Nazik, A.(2002). Benthic Foraminifera and Ostracodafaunae of the Bozcaada (Northern Aegean Sea) and local variations in the seassemblages. Yerbilimleri Geosaund, 40/41:97-119.

Nazik, A. (2001). Ostracode faunas of bottom sediments from the continenetal shelf,south Marmara Sea, NW Turkeyand their comparison with other shelf environmentsin the Mediterranean and Aegean regions. Geological Journal, 36: 111-123.

Nazik, A., Avşar, N. Meriç, E. (1999). Vertical Distribution of Holocene ostracodaat Anadolu Hisarı (Bosphorus-İstanbul), Yerbilimleri (Geosound), 35, p. 115-126.

Pielou, (1969). An Introduction to Mathematical Ecology. New York, Wiley.

Şafak, Ü. (1999). Recent Ostracoda Assemblage of the Gökçeada-Bozcaada-Dardanelles Region. Yerbilimleri (Geosound), 35: 149-172.

Salihoğlu, i. andMutlu, E. (1999). Akdeniz, Marmara Denizi, Türk BoğazlarSistemi, Karadeniz ve Atmosfer Alt projeleri. ODTÜ Deniz bilimleri enstitüsü,Ankara

Schornikov, E.N. (1969). Ostracoda, Führer der Fauna des Schwarzen Meers undDer Azov Sea. In: A.A. Vodyanitskii (ed), Frielbenden invertebraten, Crustacean.Akad. Nauk. U..s.S.R. Inst. Biol., Naukova Dumka Kiev, pp.lGJ-260.

Siegel, S. (1956). Non-parametric Statistics for the Behavioral Sciences. McGraw-Hill, New York.

Sorensen, T. (1948). A method of establishing groups of equal amplitude in plantsociology based on similar species content and its application to analyses ofvegetation on Danish commons. Biologiske Skrifte 5: 1-34.

Stambolidis, A. (1985). Zur Kenntnis Der Ostracodes des Evros-Delta (Nord-Agaisches Meer') Griechenland. Mitteilungerı aus dem Hamburg ZoologischenMuseum und Institute, 82: 155-254.

Tuğrul, S., Polat, C. (I 995). Quantitative comparison of the influxes of nutrients andorganic carbon into the Sea of Marmara both from anthropogenic sources and fromthe Black Sea. Water Science and Technology 32: 115-121.

Tuğrul, S., Salihoğlu, i. (2000). Chemical oceanography of the Marmara Sca and theTurkish straits system. "Marmara Denizi 2000" Sernpozvvrnı: :;iidıriler kitabı Türkdeniz araştırmaları vakfı, 5: 327-345.

ISI

Tunoğlu, C. (1999). Recerıt ostracoda associat inn in the Sea of Marmara, NWTurkey. Yerbilimleri, Bulletin of Earth Scierıces Application and Research Centre ofHacettepe University 21: 63-g9.

Tunoğlu, C. (2002). The recent ostracoda association of Istanbul strait exit, andZonguldak and Amasra coastal are as of Black Sea. Yerbilimleri, Bulletin of EarthSciences Application and Research Centre of Hacettepe University 26:27-43.

Yüce, R. (1972). A study of the Golden Horn for pollution and hydrography.Publications of the hydrobiological research institute, 7: 1-21.

Yüce, H. (1995). Northem Aegean water mases. Estuarine, Coastal and ShelfScience 41: 325-343.

Yüce, H., Türker, A. (1991). Marmara Denizi'nin fiziksel oşinografik özellikleri veAkdeniz suyunun Karadenize girişi. Uluslar arası çevre sorunları sempozyumutebliğleri: 284-303.

Zar, J. H. (1984). Biostatistical Analysis, 2nd edn. Prentice Hall,Englewood Cliffs,NJ.

Received:02.01.2008Accepted: 11.06.2008

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